The present invention relates to a method of and a device for determination of a position of a vehicle.
Such methods and devices are used in particular in traffic telematic devices and navigation devices of motor vehicles. For this purpose in particular location receivers for the NAVSTAR global positioning system (GPS) or the global navigation satellite system (GNSS, GLONASS) are used, which make possible a three-dimensional position determination by time measurements to the satellites. The availability and the position accuracy of such satellite signal-receiving devices can be substantially increased by incorporation of additional sensors, such as for example rotary speed sensors, acceleration sensors and a speed sensor, when the information supplied from these sensors over the covered travel paths and traveling directions are compared with the successive position signals of the navigation satellite. For this purpose generally the corresponding sensor signals and the position signals of the receiving antenna are received by a computing device, a relative position in a predetermined reference system for example a digital card is determined from a comparison of the determined position in the card and an inputted desired location of a route and subsequently a driving command is outputted to the driver of the motor vehicle, for example via a display. During the examination of the relative position in the card systematic deviations of the sensor signals can be recognized and corresponding correction data can be determined for correcting these systematic errors in the sensor signals by the computation of the relative position in the reference system.
However, such a system has problems, in particular in that during the progressive technological development specifically of the receiving antennas and vehicle condition sensors, basically the whole computation device must be replaced. Thereby an adaptation of such a system to technological changes and improvements is difficult because of high conversion costs.
Accordingly, it is an object of present invention to provide a method of and a device for determination of a position of a vehicle, which facilitates an adaptation of a navigation system to changed technical requirements.
In keeping with these objects and with others which will become apparent hereinafter, one feature of present invention resides, briefly stated, in a method for determination a position of a vehicle, in accordance with which position signals outputted by a reception antenna and traveling condition values outputted by traveling condition sensors of the vehicle are used for determination of an absolute position of the vehicle and an absolute position signal is outputted, from the absolute position signal and preliminary outputted reference data of a reference system a relative position of the vehicle in the reference system is determined, a position quality signal is determined from a comparison of the absolute position signal and a reference position signal and the position quality signal is used for determination of the absolute position of the vehicle.
An inventive device for determination of the position of a vehicle has a locating device for determination of an absolute position of the vehicle which receives the traveling condition signals of the vehicle from vehicle sensors and position signals from a reception antenna, determines an absolute position of the vehicle and makes it available as an absolute position signal, for correction of the absolute position by taking into consideration a position quality signal, and a navigation device which receives the absolute position signal and at least few traveling condition signals from the locating device, determines a relative position signal for determination of the vehicle position in a reference system, determines the position quality signal from a deviation or dispersion of the absolute position signal from the relative position signal, and makes available the locating device.
In accordance with the present invention a locating method for determination of an absolute position of the vehicle is separated from a following navigation method for determination of the relative position of the vehicle in a reference system. By this separation in two separate methods, different algorithms and sensors or reception antennas can be used for the locating method, without the necessity to provide adaptation of the subsequent navigation methods to the different locating methods, as is the case in the interconnected methods. However, the transmission of a standardized absolute position signal and a standardized position quality signal must be guaranteed, which are independent from the special sensors and reception antennas. The two separate methods can be thereby coupled with one another by standardized signal transmissions.
The inventive device correspondingly is subdivided into two separate devices, a locating device for determination of an absolute position and a navigation device for determination of a relative position and determination of a position quality signal. These devices can be exchanged separately, without the necessity to provide adaptation of the remaining device to a new used device. When new sensors or reception antennas are available for outputting of the new or more accurate signals, no more a complete computing device for determination of the relative position of the vehicles in a reference system must be exchanged. Instead the locating device can be replaced separately. Furthermore, the locating device can be separately replaced in the case of a further development of the hardware or computation algorithm. The position quality signal can be determined for example from a difference of the absolute positions and relative positions, or a correlation of the signal determined in the navigation device.
Furthermore, further traveling condition signals or a quality signals can be outputted by the locating device to the navigation device, so that the variants determined in the locating device can be reproduced from determination of the absolute position.
In the locating device algorithms can be used with which systematic deviation of the sensor signals can be calibrated by the long-term stable position signals of the reception antenna. In this cooperation, the position quality signal of the navigation device can be in particular introduced in this calibration directly. Furthermore, an introduction of different correction data in this calibration or correction is possible in the locating device.
The locating device and the navigation device can be produced preferably each as an integrated circuit. The locating device can be for example integrated in the reception antenna.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.